The lights in my 850 aren't working and the person I bought it from said the switch was broken he believes. Is that correct/common and where do I get a new one?

 

could be a LOT of things. switch might be one of them, could be a wiring issue, and its also possible that all the bulbs are just burned out. You wont know until you check them.

 

I just bought a 94 and all the lights where burnt out. When changing them most still looked good but where not.

 

Check the #16 fuse (off the top of my head) for power for the courtesy light.

Then push the manual map buttons on each side of your door switch (overhead panel)...those should turn on the light regardless of the door position.

If they do not turn on, check your bulbs. If they are good remove the overhead panel and with a test light check for power in the plug. There should be two wires with power on them, one if for the map lights and the other is for the seatbelt indicators.

If there is power then the problem is with the switch or door pins(very unlikely the door pins).

You can jumper the switch to bypass it and still have it work. I have done it but dont think I can explain what spots to jump, there are two but you lose the ability to manually turn it on and off...but youll have light with the doors. If I get a chance I will take a picture of this setup. I actually did it just last night for my other Volvo I am selling.

Option 2, go buy a new switch.